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-rw-r--r--crypto/openssh/packet.c401
1 files changed, 244 insertions, 157 deletions
diff --git a/crypto/openssh/packet.c b/crypto/openssh/packet.c
index 3216fda..00109ea 100644
--- a/crypto/openssh/packet.c
+++ b/crypto/openssh/packet.c
@@ -37,13 +37,12 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: packet.c,v 1.38 2000/10/12 14:21:12 markus Exp $");
+RCSID("$OpenBSD: packet.c,v 1.61 2001/04/05 10:42:51 markus Exp $");
#include "xmalloc.h"
#include "buffer.h"
#include "packet.h"
#include "bufaux.h"
-#include "ssh.h"
#include "crc32.h"
#include "getput.h"
@@ -52,15 +51,14 @@ RCSID("$OpenBSD: packet.c,v 1.38 2000/10/12 14:21:12 markus Exp $");
#include "channels.h"
#include "compat.h"
+#include "ssh1.h"
#include "ssh2.h"
-#include <openssl/bn.h>
-#include <openssl/dh.h>
-#include <openssl/hmac.h>
-#include "buffer.h"
#include "cipher.h"
#include "kex.h"
-#include "hmac.h"
+#include "mac.h"
+#include "log.h"
+#include "canohost.h"
#ifdef PACKET_DEBUG
#define DBG(x) x
@@ -84,7 +82,7 @@ static int connection_out = -1;
static int cipher_type = SSH_CIPHER_NONE;
/* Protocol flags for the remote side. */
-static unsigned int remote_protocol_flags = 0;
+static u_int remote_protocol_flags = 0;
/* Encryption context for receiving data. This is only used for decryption. */
static CipherContext receive_context;
@@ -106,6 +104,7 @@ static Buffer incoming_packet;
/* Scratch buffer for packet compression/decompression. */
static Buffer compression_buffer;
+static int compression_buffer_ready = 0;
/* Flag indicating whether packet compression/decompression is enabled. */
static int packet_compression = 0;
@@ -123,35 +122,14 @@ static int interactive_mode = 0;
int use_ssh2_packet_format = 0;
/* Session key information for Encryption and MAC */
-Kex *kex = NULL;
+Newkeys *newkeys[MODE_MAX];
void
-packet_set_kex(Kex *k)
-{
- if( k->mac[MODE_IN ].key == NULL ||
- k->enc[MODE_IN ].key == NULL ||
- k->enc[MODE_IN ].iv == NULL ||
- k->mac[MODE_OUT].key == NULL ||
- k->enc[MODE_OUT].key == NULL ||
- k->enc[MODE_OUT].iv == NULL)
- fatal("bad KEX");
- kex = k;
-}
-void
-clear_enc_keys(Enc *enc, int len)
-{
- memset(enc->iv, 0, len);
- memset(enc->key, 0, len);
- xfree(enc->iv);
- xfree(enc->key);
- enc->iv = NULL;
- enc->key = NULL;
-}
-void
packet_set_ssh2_format(void)
{
DBG(debug("use_ssh2_packet_format"));
use_ssh2_packet_format = 1;
+ newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL;
}
/*
@@ -167,8 +145,8 @@ packet_set_connection(int fd_in, int fd_out)
connection_in = fd_in;
connection_out = fd_out;
cipher_type = SSH_CIPHER_NONE;
- cipher_init(&send_context, none, (unsigned char *) "", 0, NULL, 0);
- cipher_init(&receive_context, none, (unsigned char *) "", 0, NULL, 0);
+ cipher_init(&send_context, none, (u_char *) "", 0, NULL, 0);
+ cipher_init(&receive_context, none, (u_char *) "", 0, NULL, 0);
if (!initialized) {
initialized = 1;
buffer_init(&input);
@@ -272,7 +250,7 @@ packet_close()
buffer_free(&output);
buffer_free(&outgoing_packet);
buffer_free(&incoming_packet);
- if (packet_compression) {
+ if (compression_buffer_ready) {
buffer_free(&compression_buffer);
buffer_compress_uninit();
}
@@ -281,7 +259,7 @@ packet_close()
/* Sets remote side protocol flags. */
void
-packet_set_protocol_flags(unsigned int protocol_flags)
+packet_set_protocol_flags(u_int protocol_flags)
{
remote_protocol_flags = protocol_flags;
channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0);
@@ -289,7 +267,7 @@ packet_set_protocol_flags(unsigned int protocol_flags)
/* Returns the remote protocol flags set earlier by the above function. */
-unsigned int
+u_int
packet_get_protocol_flags()
{
return remote_protocol_flags;
@@ -300,15 +278,24 @@ packet_get_protocol_flags()
* Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
*/
-/*** XXXXX todo: kex means re-init */
+void
+packet_init_compression()
+{
+ if (compression_buffer_ready == 1)
+ return;
+ compression_buffer_ready = 1;
+ buffer_init(&compression_buffer);
+}
+
void
packet_start_compression(int level)
{
- if (packet_compression)
+ if (packet_compression && !use_ssh2_packet_format)
fatal("Compression already enabled.");
packet_compression = 1;
- buffer_init(&compression_buffer);
- buffer_compress_init(level);
+ packet_init_compression();
+ buffer_compress_init_send(level);
+ buffer_compress_init_recv();
}
/*
@@ -318,7 +305,7 @@ packet_start_compression(int level)
void
packet_encrypt(CipherContext * cc, void *dest, void *src,
- unsigned int bytes)
+ u_int bytes)
{
cipher_encrypt(cc, dest, src, bytes);
}
@@ -329,7 +316,7 @@ packet_encrypt(CipherContext * cc, void *dest, void *src,
*/
void
-packet_decrypt(CipherContext *context, void *dest, void *src, unsigned int bytes)
+packet_decrypt(CipherContext *context, void *dest, void *src, u_int bytes)
{
/*
* Cryptographic attack detector for ssh - Modifications for packet.c
@@ -350,7 +337,7 @@ packet_decrypt(CipherContext *context, void *dest, void *src, unsigned int bytes
*/
void
-packet_set_encryption_key(const unsigned char *key, unsigned int keylen,
+packet_set_encryption_key(const u_char *key, u_int keylen,
int number)
{
Cipher *cipher = cipher_by_number(number);
@@ -391,7 +378,7 @@ packet_start2(int type)
void
packet_start(int type)
{
- DBG(debug("packet_start[%d]",type));
+ DBG(debug("packet_start[%d]", type));
if (use_ssh2_packet_format)
packet_start2(type);
else
@@ -410,7 +397,7 @@ packet_put_char(int value)
/* Appends an integer to the packet data. */
void
-packet_put_int(unsigned int value)
+packet_put_int(u_int value)
{
buffer_put_int(&outgoing_packet, value);
}
@@ -418,7 +405,7 @@ packet_put_int(unsigned int value)
/* Appends a string to packet data. */
void
-packet_put_string(const char *buf, unsigned int len)
+packet_put_string(const char *buf, u_int len)
{
buffer_put_string(&outgoing_packet, buf, len);
}
@@ -429,7 +416,7 @@ packet_put_cstring(const char *str)
}
void
-packet_put_raw(const char *buf, unsigned int len)
+packet_put_raw(const char *buf, u_int len)
{
buffer_append(&outgoing_packet, buf, len);
}
@@ -454,11 +441,11 @@ packet_put_bignum2(BIGNUM * value)
*/
void
-packet_send1()
+packet_send1(void)
{
char buf[8], *cp;
int i, padding, len;
- unsigned int checksum;
+ u_int checksum;
u_int32_t rand = 0;
/*
@@ -493,7 +480,7 @@ packet_send1()
buffer_consume(&outgoing_packet, 8 - padding);
/* Add check bytes. */
- checksum = ssh_crc32((unsigned char *) buffer_ptr(&outgoing_packet),
+ checksum = ssh_crc32((u_char *) buffer_ptr(&outgoing_packet),
buffer_len(&outgoing_packet));
PUT_32BIT(buf, checksum);
buffer_append(&outgoing_packet, buf, 4);
@@ -524,28 +511,78 @@ packet_send1()
*/
}
+void
+set_newkeys(int mode)
+{
+ Enc *enc;
+ Mac *mac;
+ Comp *comp;
+ CipherContext *cc;
+
+ debug("newkeys: mode %d", mode);
+
+ cc = (mode == MODE_OUT) ? &send_context : &receive_context;
+ if (newkeys[mode] != NULL) {
+ debug("newkeys: rekeying");
+ /* todo: free old keys, reset compression/cipher-ctxt; */
+ memset(cc, 0, sizeof(*cc));
+ enc = &newkeys[mode]->enc;
+ mac = &newkeys[mode]->mac;
+ comp = &newkeys[mode]->comp;
+ memset(mac->key, 0, mac->key_len);
+ xfree(enc->name);
+ xfree(enc->iv);
+ xfree(enc->key);
+ xfree(mac->name);
+ xfree(mac->key);
+ xfree(comp->name);
+ xfree(newkeys[mode]);
+ }
+ newkeys[mode] = kex_get_newkeys(mode);
+ if (newkeys[mode] == NULL)
+ fatal("newkeys: no keys for mode %d", mode);
+ enc = &newkeys[mode]->enc;
+ mac = &newkeys[mode]->mac;
+ comp = &newkeys[mode]->comp;
+ if (mac->md != NULL)
+ mac->enabled = 1;
+ DBG(debug("cipher_init_context: %d", mode));
+ cipher_init(cc, enc->cipher, enc->key, enc->cipher->key_len,
+ enc->iv, enc->cipher->block_size);
+ memset(enc->iv, 0, enc->cipher->block_size);
+ memset(enc->key, 0, enc->cipher->key_len);
+ if (comp->type != 0 && comp->enabled == 0) {
+ packet_init_compression();
+ if (mode == MODE_OUT)
+ buffer_compress_init_send(6);
+ else
+ buffer_compress_init_recv();
+ comp->enabled = 1;
+ }
+}
+
/*
* Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
*/
void
-packet_send2()
+packet_send2(void)
{
- unsigned char *macbuf = NULL;
+ static u_int32_t seqnr = 0;
+ u_char *macbuf = NULL;
char *cp;
- unsigned int packet_length = 0;
- unsigned int i, padlen, len;
+ u_int packet_length = 0;
+ u_int i, padlen, len;
u_int32_t rand = 0;
- static unsigned int seqnr = 0;
int type;
Enc *enc = NULL;
Mac *mac = NULL;
Comp *comp = NULL;
int block_size;
- if (kex != NULL) {
- enc = &kex->enc[MODE_OUT];
- mac = &kex->mac[MODE_OUT];
- comp = &kex->comp[MODE_OUT];
+ if (newkeys[MODE_OUT] != NULL) {
+ enc = &newkeys[MODE_OUT]->enc;
+ mac = &newkeys[MODE_OUT]->mac;
+ comp = &newkeys[MODE_OUT]->comp;
}
block_size = enc ? enc->cipher->block_size : 8;
@@ -588,7 +625,7 @@ packet_send2()
if (i % 4 == 0)
rand = arc4random();
cp[i] = rand & 0xff;
- rand <<= 8;
+ rand >>= 8;
}
} else {
/* clear padding */
@@ -603,11 +640,9 @@ packet_send2()
/* compute MAC over seqnr and packet(length fields, payload, padding) */
if (mac && mac->enabled) {
- macbuf = hmac( mac->md, seqnr,
- (unsigned char *) buffer_ptr(&outgoing_packet),
- buffer_len(&outgoing_packet),
- mac->key, mac->key_len
- );
+ macbuf = mac_compute(mac, seqnr,
+ (u_char *) buffer_ptr(&outgoing_packet),
+ buffer_len(&outgoing_packet));
DBG(debug("done calc MAC out #%d", seqnr));
}
/* encrypt packet and append to output buffer. */
@@ -626,22 +661,8 @@ packet_send2()
log("outgoing seqnr wraps around");
buffer_clear(&outgoing_packet);
- if (type == SSH2_MSG_NEWKEYS) {
- if (kex==NULL || mac==NULL || enc==NULL || comp==NULL)
- fatal("packet_send2: no KEX");
- if (mac->md != NULL)
- mac->enabled = 1;
- DBG(debug("cipher_init send_context"));
- cipher_init(&send_context, enc->cipher,
- enc->key, enc->cipher->key_len,
- enc->iv, enc->cipher->block_size);
- clear_enc_keys(enc, kex->we_need);
- if (comp->type != 0 && comp->enabled == 0) {
- comp->enabled = 1;
- if (! packet_compression)
- packet_start_compression(6);
- }
- }
+ if (type == SSH2_MSG_NEWKEYS)
+ set_newkeys(MODE_OUT);
}
void
@@ -664,10 +685,13 @@ int
packet_read(int *payload_len_ptr)
{
int type, len;
- fd_set set;
+ fd_set *setp;
char buf[8192];
DBG(debug("packet_read()"));
+ setp = (fd_set *)xmalloc(howmany(connection_in+1, NFDBITS) *
+ sizeof(fd_mask));
+
/* Since we are blocking, ensure that all written packets have been sent. */
packet_write_wait();
@@ -682,17 +706,22 @@ packet_read(int *payload_len_ptr)
|| type == SSH_CMSG_EXIT_CONFIRMATION))
packet_integrity_check(*payload_len_ptr, 0, type);
/* If we got a packet, return it. */
- if (type != SSH_MSG_NONE)
+ if (type != SSH_MSG_NONE) {
+ xfree(setp);
return type;
+ }
/*
* Otherwise, wait for some data to arrive, add it to the
* buffer, and try again.
*/
- FD_ZERO(&set);
- FD_SET(connection_in, &set);
+ memset(setp, 0, howmany(connection_in + 1, NFDBITS) *
+ sizeof(fd_mask));
+ FD_SET(connection_in, setp);
/* Wait for some data to arrive. */
- select(connection_in + 1, &set, NULL, NULL, NULL);
+ while (select(connection_in + 1, setp, NULL, NULL, NULL) == -1 &&
+ (errno == EAGAIN || errno == EINTR))
+ ;
/* Read data from the socket. */
len = read(connection_in, buf, sizeof(buf));
@@ -742,16 +771,16 @@ packet_read_expect(int *payload_len_ptr, int expected_type)
int
packet_read_poll1(int *payload_len_ptr)
{
- unsigned int len, padded_len;
- unsigned char *ucp;
+ u_int len, padded_len;
+ u_char *ucp;
char buf[8], *cp;
- unsigned int checksum, stored_checksum;
+ u_int checksum, stored_checksum;
/* Check if input size is less than minimum packet size. */
if (buffer_len(&input) < 4 + 8)
return SSH_MSG_NONE;
/* Get length of incoming packet. */
- ucp = (unsigned char *) buffer_ptr(&input);
+ ucp = (u_char *) buffer_ptr(&input);
len = GET_32BIT(ucp);
if (len < 1 + 2 + 2 || len > 256 * 1024)
packet_disconnect("Bad packet length %d.", len);
@@ -778,7 +807,7 @@ packet_read_poll1(int *payload_len_ptr)
#endif
/* Compute packet checksum. */
- checksum = ssh_crc32((unsigned char *) buffer_ptr(&incoming_packet),
+ checksum = ssh_crc32((u_char *) buffer_ptr(&incoming_packet),
buffer_len(&incoming_packet) - 4);
/* Skip padding. */
@@ -790,7 +819,7 @@ packet_read_poll1(int *payload_len_ptr)
packet_disconnect("packet_read_poll: len %d != buffer_len %d.",
len, buffer_len(&incoming_packet));
- ucp = (unsigned char *) buffer_ptr(&incoming_packet) + len - 4;
+ ucp = (u_char *) buffer_ptr(&incoming_packet) + len - 4;
stored_checksum = GET_32BIT(ucp);
if (checksum != stored_checksum)
packet_disconnect("Corrupted check bytes on input.");
@@ -811,28 +840,28 @@ packet_read_poll1(int *payload_len_ptr)
*payload_len_ptr = buffer_len(&incoming_packet);
/* Return type. */
- return (unsigned char) buf[0];
+ return (u_char) buf[0];
}
int
packet_read_poll2(int *payload_len_ptr)
{
- unsigned int padlen, need;
- unsigned char buf[8], *macbuf;
- unsigned char *ucp;
+ static u_int32_t seqnr = 0;
+ static u_int packet_length = 0;
+ u_int padlen, need;
+ u_char buf[8], *macbuf;
+ u_char *ucp;
char *cp;
- static unsigned int packet_length = 0;
- static unsigned int seqnr = 0;
int type;
int maclen, block_size;
Enc *enc = NULL;
Mac *mac = NULL;
Comp *comp = NULL;
- if (kex != NULL) {
- enc = &kex->enc[MODE_IN];
- mac = &kex->mac[MODE_IN];
- comp = &kex->comp[MODE_IN];
+ if (newkeys[MODE_IN] != NULL) {
+ enc = &newkeys[MODE_IN]->enc;
+ mac = &newkeys[MODE_IN]->mac;
+ comp = &newkeys[MODE_IN]->comp;
}
maclen = mac && mac->enabled ? mac->mac_len : 0;
block_size = enc ? enc->cipher->block_size : 8;
@@ -848,7 +877,7 @@ packet_read_poll2(int *payload_len_ptr)
buffer_append_space(&incoming_packet, &cp, block_size);
packet_decrypt(&receive_context, cp, buffer_ptr(&input),
block_size);
- ucp = (unsigned char *) buffer_ptr(&incoming_packet);
+ ucp = (u_char *) buffer_ptr(&incoming_packet);
packet_length = GET_32BIT(ucp);
if (packet_length < 1 + 4 || packet_length > 256 * 1024) {
buffer_dump(&incoming_packet);
@@ -882,11 +911,9 @@ packet_read_poll2(int *payload_len_ptr)
* increment sequence number for incoming packet
*/
if (mac && mac->enabled) {
- macbuf = hmac( mac->md, seqnr,
- (unsigned char *) buffer_ptr(&incoming_packet),
- buffer_len(&incoming_packet),
- mac->key, mac->key_len
- );
+ macbuf = mac_compute(mac, seqnr,
+ (u_char *) buffer_ptr(&incoming_packet),
+ buffer_len(&incoming_packet));
if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0)
packet_disconnect("Corrupted MAC on input.");
DBG(debug("MAC #%d ok", seqnr));
@@ -926,30 +953,16 @@ packet_read_poll2(int *payload_len_ptr)
packet_length = 0;
/* extract packet type */
- type = (unsigned char)buf[0];
-
- if (type == SSH2_MSG_NEWKEYS) {
- if (kex==NULL || mac==NULL || enc==NULL || comp==NULL)
- fatal("packet_read_poll2: no KEX");
- if (mac->md != NULL)
- mac->enabled = 1;
- DBG(debug("cipher_init receive_context"));
- cipher_init(&receive_context, enc->cipher,
- enc->key, enc->cipher->key_len,
- enc->iv, enc->cipher->block_size);
- clear_enc_keys(enc, kex->we_need);
- if (comp->type != 0 && comp->enabled == 0) {
- comp->enabled = 1;
- if (! packet_compression)
- packet_start_compression(6);
- }
- }
+ type = (u_char)buf[0];
+
+ if (type == SSH2_MSG_NEWKEYS)
+ set_newkeys(MODE_IN);
#ifdef PACKET_DEBUG
- fprintf(stderr, "read/plain[%d]:\r\n",type);
+ fprintf(stderr, "read/plain[%d]:\r\n", type);
buffer_dump(&incoming_packet);
#endif
- return (unsigned char)type;
+ return (u_char)type;
}
int
@@ -979,14 +992,15 @@ packet_read_poll(int *payload_len_ptr)
case SSH2_MSG_DISCONNECT:
reason = packet_get_int();
msg = packet_get_string(NULL);
- log("Received disconnect: %d: %.900s", reason, msg);
+ log("Received disconnect from %s: %d: %.400s", get_remote_ipaddr(),
+ reason, msg);
xfree(msg);
fatal_cleanup();
break;
default:
return type;
break;
- }
+ }
} else {
switch(type) {
case SSH_MSG_IGNORE:
@@ -998,7 +1012,8 @@ packet_read_poll(int *payload_len_ptr)
break;
case SSH_MSG_DISCONNECT:
msg = packet_get_string(NULL);
- log("Received disconnect: %.900s", msg);
+ log("Received disconnect from %s: %.400s", get_remote_ipaddr(),
+ msg);
fatal_cleanup();
xfree(msg);
break;
@@ -1007,7 +1022,7 @@ packet_read_poll(int *payload_len_ptr)
DBG(debug("received packet type %d", type));
return type;
break;
- }
+ }
}
}
}
@@ -1018,24 +1033,24 @@ packet_read_poll(int *payload_len_ptr)
*/
void
-packet_process_incoming(const char *buf, unsigned int len)
+packet_process_incoming(const char *buf, u_int len)
{
buffer_append(&input, buf, len);
}
/* Returns a character from the packet. */
-unsigned int
+u_int
packet_get_char()
{
char ch;
buffer_get(&incoming_packet, &ch, 1);
- return (unsigned char) ch;
+ return (u_char) ch;
}
/* Returns an integer from the packet data. */
-unsigned int
+u_int
packet_get_int()
{
return buffer_get_int(&incoming_packet);
@@ -1081,7 +1096,7 @@ packet_remaining(void)
*/
char *
-packet_get_string(unsigned int *length_ptr)
+packet_get_string(u_int *length_ptr)
{
return buffer_get_string(&incoming_packet, length_ptr);
}
@@ -1101,6 +1116,9 @@ packet_send_debug(const char *fmt,...)
char buf[1024];
va_list args;
+ if (compat20 && (datafellows & SSH_BUG_DEBUG))
+ return;
+
va_start(args, fmt);
vsnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
@@ -1193,14 +1211,21 @@ packet_write_poll()
void
packet_write_wait()
{
+ fd_set *setp;
+
+ setp = (fd_set *)xmalloc(howmany(connection_out + 1, NFDBITS) *
+ sizeof(fd_mask));
packet_write_poll();
while (packet_have_data_to_write()) {
- fd_set set;
- FD_ZERO(&set);
- FD_SET(connection_out, &set);
- select(connection_out + 1, NULL, &set, NULL, NULL);
+ memset(setp, 0, howmany(connection_out + 1, NFDBITS) *
+ sizeof(fd_mask));
+ FD_SET(connection_out, setp);
+ while (select(connection_out + 1, NULL, setp, NULL, NULL) == -1 &&
+ (errno == EAGAIN || errno == EINTR))
+ ;
packet_write_poll();
}
+ xfree(setp);
}
/* Returns true if there is buffered data to write to the connection. */
@@ -1225,45 +1250,45 @@ packet_not_very_much_data_to_write()
/* Informs that the current session is interactive. Sets IP flags for that. */
void
-packet_set_interactive(int interactive, int keepalives)
+packet_set_interactive(int interactive)
{
+ static int called = 0;
+ int lowdelay = IPTOS_LOWDELAY;
+ int throughput = IPTOS_THROUGHPUT;
int on = 1;
+ if (called)
+ return;
+ called = 1;
+
/* Record that we are in interactive mode. */
interactive_mode = interactive;
/* Only set socket options if using a socket. */
if (!packet_connection_is_on_socket())
return;
- if (keepalives) {
- /* Set keepalives if requested. */
- if (setsockopt(connection_in, SOL_SOCKET, SO_KEEPALIVE, (void *) &on,
- sizeof(on)) < 0)
- error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
- }
/*
- * IPTOS_LOWDELAY, TCP_NODELAY and IPTOS_THROUGHPUT are IPv4 only
+ * IPTOS_LOWDELAY and IPTOS_THROUGHPUT are IPv4 only
*/
- if (!packet_connection_is_ipv4())
- return;
if (interactive) {
/*
* Set IP options for an interactive connection. Use
* IPTOS_LOWDELAY and TCP_NODELAY.
*/
- int lowdelay = IPTOS_LOWDELAY;
- if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &lowdelay,
- sizeof(lowdelay)) < 0)
- error("setsockopt IPTOS_LOWDELAY: %.100s", strerror(errno));
+ if (packet_connection_is_ipv4()) {
+ if (setsockopt(connection_in, IPPROTO_IP, IP_TOS,
+ (void *) &lowdelay, sizeof(lowdelay)) < 0)
+ error("setsockopt IPTOS_LOWDELAY: %.100s",
+ strerror(errno));
+ }
if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on,
sizeof(on)) < 0)
error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
- } else {
+ } else if (packet_connection_is_ipv4()) {
/*
* Set IP options for a non-interactive connection. Use
* IPTOS_THROUGHPUT.
*/
- int throughput = IPTOS_THROUGHPUT;
if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput,
sizeof(throughput)) < 0)
error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno));
@@ -1295,3 +1320,65 @@ packet_set_maxsize(int s)
max_packet_size = s;
return s;
}
+
+/*
+ * 9.2. Ignored Data Message
+ *
+ * byte SSH_MSG_IGNORE
+ * string data
+ *
+ * All implementations MUST understand (and ignore) this message at any
+ * time (after receiving the protocol version). No implementation is
+ * required to send them. This message can be used as an additional
+ * protection measure against advanced traffic analysis techniques.
+ */
+/* size of current + ignore message should be n*sumlen bytes (w/o mac) */
+void
+packet_inject_ignore(int sumlen)
+{
+ int blocksize, padlen, have, need, nb, mini, nbytes;
+ Enc *enc = NULL;
+
+ if (use_ssh2_packet_format == 0)
+ return;
+
+ have = buffer_len(&outgoing_packet);
+ debug2("packet_inject_ignore: current %d", have);
+ if (newkeys[MODE_OUT] != NULL)
+ enc = &newkeys[MODE_OUT]->enc;
+ blocksize = enc ? enc->cipher->block_size : 8;
+ padlen = blocksize - (have % blocksize);
+ if (padlen < 4)
+ padlen += blocksize;
+ have += padlen;
+ have /= blocksize; /* # of blocks for current message */
+
+ nb = roundup(sumlen, blocksize) / blocksize; /* blocks for both */
+ mini = roundup(5+1+4+4, blocksize) / blocksize; /* minsize ignore msg */
+ need = nb - (have % nb); /* blocks for ignore */
+ if (need <= mini)
+ need += nb;
+ nbytes = (need - mini) * blocksize; /* size of ignore payload */
+ debug2("packet_inject_ignore: block %d have %d nb %d mini %d need %d",
+ blocksize, have, nb, mini, need);
+
+ /* enqueue current message and append a ignore message */
+ packet_send();
+ packet_send_ignore(nbytes);
+}
+
+void
+packet_send_ignore(int nbytes)
+{
+ u_int32_t rand = 0;
+ int i;
+
+ packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
+ packet_put_int(nbytes);
+ for(i = 0; i < nbytes; i++) {
+ if (i % 4 == 0)
+ rand = arc4random();
+ packet_put_char(rand & 0xff);
+ rand >>= 8;
+ }
+}
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